Fix hydration with custom _app and granular chunks (#10144)

* Add failing hydration test * Add importing of next/router to _app * Fix type * Update _app check for windows * Remove babel fix * Update to use webpack to require next/router
vercel · Jan 17, 2020 · 5a9a478 · 5a9a478
1 parent aa6991f
commit 5a9a478
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Showing 7 changed files with 72 additions and 2 deletions.
diff --git a/packages/next/build/entries.ts b/packages/next/build/entries.ts
@@ -115,10 +115,19 @@ export function createEntrypoints(
     }
 
     if (!isApiRoute) {
-      client[bundlePath] = `next-client-pages-loader?${stringify({
+      const pageLoader = `next-client-pages-loader?${stringify({
         page,
         absolutePagePath,
       })}!`
+
+      // Make sure next/router is a dependency of _app or else granularChunks
+      // might cause the router to not be able to load causing hydration
+      // to fail
+
+      client[bundlePath] =
+        page === '/_app'
+          ? [pageLoader, require.resolve('../client/router')]
+          : pageLoader
     }
   })
 

diff --git a/packages/next/pages/_app.tsx b/packages/next/pages/_app.tsx
@@ -7,7 +7,6 @@ import {
   AppPropsType,
 } from '../next-server/lib/utils'
 import { Router } from '../client/router'
-import '../client/router'
 
 export { AppInitialProps }
 

diff --git a/test/integration/hydration/pages/_app.js b/test/integration/hydration/pages/_app.js
@@ -0,0 +1 @@
+export default ({ Component, pageProps }) => <Component {...pageProps} />
diff --git a/test/integration/hydration/pages/_document.js b/test/integration/hydration/pages/_document.js
@@ -0,0 +1,16 @@
+import Document, { Head, Html, Main, NextScript } from 'next/document'
+import React from 'react'
+
+class WeddingDocument extends Document {
+  render() {
+    return (
+      <Html lang="en-GB">
+        <Head />
+        <Main />
+        <NextScript />
+      </Html>
+    )
+  }
+}
+
+export default WeddingDocument
diff --git a/test/integration/hydration/pages/details.js b/test/integration/hydration/pages/details.js
@@ -0,0 +1,6 @@
+export default () => {
+  if (typeof window !== 'undefined') {
+    window.didHydrate = true
+  }
+  return 'details'
+}
diff --git a/test/integration/hydration/pages/index.js b/test/integration/hydration/pages/index.js
@@ -0,0 +1,6 @@
+export default () => {
+  if (typeof window !== 'undefined') {
+    window.didHydrate = true
+  }
+  return 'index'
+}
diff --git a/test/integration/hydration/test/index.test.js b/test/integration/hydration/test/index.test.js
@@ -0,0 +1,33 @@
+/* eslint-env jest */
+/* global jasmine */
+import path from 'path'
+import fs from 'fs-extra'
+import webdriver from 'next-webdriver'
+import {
+  nextBuild,
+  nextStart,
+  findPort,
+  waitFor,
+  killApp,
+} from 'next-test-utils'
+
+jasmine.DEFAULT_TIMEOUT_INTERVAL = 1000 * 60 * 1
+const appDir = path.join(__dirname, '..')
+let app
+let appPort
+
+describe('Hydration', () => {
+  beforeAll(async () => {
+    await fs.remove(path.join(appDir, '.next'))
+    await nextBuild(appDir)
+    appPort = await findPort()
+    app = await nextStart(appDir, appPort)
+  })
+  afterAll(() => killApp(app))
+
+  it('Hydrates correctly', async () => {
+    const browser = await webdriver(appPort, '/')
+    await waitFor(2000)
+    expect(await browser.eval('window.didHydrate')).toBe(true)
+  })
+})